Elastic-fluid turbine



Dec. 3, 1929. H. F. SCHMIDT 1,737,736

ELASTIC FLUID TURBINE Filed Dec. 27, 1924 2 Sheets-Sheet 1 F 5 66 62 ggz. I

fifficb'mim. WITNESSES: INVENTOR ATTORNEY Dec. 3, 1929. H. F. SCHMIDT ELASTIC FLUID TURBINE Filed Dec. 27, 1924 2 sheets-sheet 2 Hf. scbmidr.

INVENTOR t Ila WITNESS ATTORN EY Patented Dec. 3, 1929 UN I T HENRY F. SCHMIDT, OF LANSDOWNE, PENNSYLVANIA, ASSIGNOR TO WES'I'm'G-HOUSE ELECTRIC & MANUFACTURING COMPANY, A CORPORATION OF PENNSYLVANIA ELASTIC-FLUID TURBINE Application filed December 27, 1924. Serial No. 758,422.

My invention relates to elastic-fluid turbines, more particularly to that type usually employed for driving small electric generators, such for example, as are employed with locomotive headlight sets and similar uses, and has for its object the provision of ap paratus of the character designated which shall be simple of design, reliable of operation, and which shall embody an efficient fluid-pressure operated governor and a forced feed lubricating system.

Apparatus embodying features of my invention is illustrated in drawings forming a part of this specification in which Figs. 1 and 2 are front and side elevations, respectively, of a turbo-generator made in accordance with my invention; Fig. 3 is a view similar to Fig. 2, shown partially in section in order to show the working parts of the "apparatus; Fig. 4 is a view showing a modified form of the invention; and Fig. 5 is a sectional view showing a modified detail of the invention.

In the design of small turbo-generators, especially those used in locomotive headlight sets, difficulties have been encountered in providing apparatus of sufficiently rugged design to withstand the extremely hard service conditions to which it is subjected and at the same time to provide a regulating means therefor that shall maintain a fairly constant voltage' with little attention. Various forms of regulating means have been employed, usually embodying some type of centrifugal force governor which, in order to secure compactness of design and better operation, is enclosed within the turbine casing and surrounded by the exhaust steam. In such apparatus, impurities carried over from the boiler to the turbine in the steam supply cor rode the working parts of the regulating apparatus, impairing its proper functioning. The working parts of the regulating apparatus, being normally inaccessible for inspection and adjustment from the outside, have also presented difliculties.

In such apparatus various means for lubricating the turbo-generator bearings have been provided separate from the regulating or governing system and involving the regular attention of the operator. Failing of such regular attention, the bearings have at times failed, rendering the apparatus inoperative. In accordance with my invention I provide a turbine and a generator mounted on a common shaft and having a readily accessible fluid-pressure operated governor. Fluid pressure varyin as a function of the speed of the turbine is eveloped by a centrifugal pump driven by the shaft. The bearings of the turbo-generator are lubricated by fluid under pressure developed by the pump. I also include means in the governor for reducing the fluid pressure before its passage to the bearings.

In order that the pump may at all times have a constant supply of fluid at its inlet, I dispose the turbo-generator shaft substantially vertically, such as is shown in the copending application of Francis Hodgkinson, Serial No. 758,406 (Patent 1,623,999, April 12, 1927) filed concurrently herewith and assigned to the Westinghouse Electric & Manufacturing Company. I provide a fluid reservoir at the lower end of the shaft and immerse the centrifugal pump within the reservoir.

Inasmuch as the generator voltage varies with its speed, it is desirable that means be included for indicating at all times the speed of the apparatus. The pressure of the fluid delivered by the centrifugal pump being a function of the speed at which it rotates, I provide means responsive to the pressure delivered by the pump for indicating the speed of the turbine.

Referring now to the drawings for a better understanding of my invention, I show in Figs. 1 and 2, at 10, a housing which encloses the turbo-generator to be described later. The housing 10 is mounted upon a hollow base 11, Which forms a fluid reservoir, and is secured thereto by means of two bolts 12 and 13. Steam or other motive fluid is admitted to the housing 10 through an opening 14 and after being employed for useful work in the turbine, is exhausted through a second opening 16. At 17 is shown a fluid-pressure operated governor for controlling the speed of the turbo-generator and at 18 a conduit ing the turbine.

controlled by the fluid-pressure operated govj bearing 24 suitably supported near the upperv end of the shaft from the housing 10 and is provided with a sleeve guide bearing 26 near its lower end. Mounted withinthe fluid reservoir 11 is a centrifugal pump 27 having an impeller 28. The impeller 28 is provided with a recessed portion 29 into which fits a projection 31 formed on the end of the shaft 22. The projection 31 freely slides into the recessed portion 29 but cannot turn therein.

To disassemble the apparatus, the bolts 12 and 13 are loosened, the turbine and generator are removed from the fluid reservoir, and the 'projection 31 of the shaft 22' slides freely out of the pump 27. I, p

(Motive fluid admitted to the turbine at 14 passes a ball admission valve 32 into a nozzle 33 Where it is expanded and directed against a series ofb-lades-36-36 of the rotor 21, driv- The admission valve 32 is ernor 17 which will now be described.

The fluid-pressure operated governor 17 comprises a cylinder 37 having an operating piston 38 therein, said operating piston being subjected, on its lower side, to thepressure developed by the pump 27 through a passage 39. Movements of the piston 38 are transmitted to the admission valve 32 through a rod 41 and a stem 42. The rod 41 is held in abutting relation to the piston 38 by means of a spring 43 disposed between an adjustable abutment 44 on' the rod 41 and a fixed abutment 46 supported by the housing. It will be seen that the spring 43 thus tends to force the piston 38 downwardly. The admission valve 32 is moved in an opening direction by the pressure entering the turbine and is moved in a closing direction by the force of" the governing fluid acting against the under side of the piston 38 forcing it upwardly against the force exerted by the spring 43. Access to the spring 43 for the purpose of adjusting the governor is had through a removable cover 47 disposed between the cylinder 37 and the eating the upper ball bearing 24, I accordingly provide means for reducing the fluid pressure delivered by, the pump 27 before its passage to the bearing. For this purpose the piston-38is made relatively long and is provided with a restricted body portion 51 which, in cooperation with the walls of the cylinder 37, provides a restricted passage serving to reduce the pressure of the fluid flowing therethrough in proportion to its length. The lower end of the piston 38 is provided with ports 52 permitting a free passage of the fluid at a relatively high pressure to. the restricted passage surrounding the portion 51. After being reduced in pressure the fluid passes through a port 53 (indicated by dotted lines) in the cylinder 37 into the conduit 18, thence through a passage 54 to the bearing 24. After lubricating the bearing 24 the fluid drains back to the reservoir 11 through a passage 56 (shown in dotted lines).

The advantage of using the clearance between the piston and the cylinder to reduce the pressure of the oil supplied to the bearing '24 is that it provides a restricted passage ororiflce which is self-cleaping. The governor piston 51 moves back and forth during operation of the turbine, thereby keeping the passage open. A further advantage is that a part ofthe leakage by the governor piston, which is always unavoidable, is utilized to supply the oil.

' In order to provide a cooling means for the fluid in the oil reservoir'I provide a nozzle 57 in the volute of the pump 27 designed to discharge a part of'the fluid under pressure developed by rotation of the impeller 28, tangentially from the pump into the reservoir 11, thus inducing a whirling circulation of fluid in the reservoir. The reservoir is provided with a coil 67 throughwhich water may be circulated for cooling the fluid therein. Waterfor this purpose may be introduced from any convenient source through an opening 66 and passing out of the coil at 68.

At 58 I show a port leading from the lower end of the cylinder 37 tothe fluid-pressure responsive tachometer 19. The tachometer 19 may be of any well-known form of pressure gauge calibrated to revolutions per minute instead of units of pressure. Inasmuch as the fluid pressure developed by the pump 27 vvaries as the square of the speed of the turthrough the turbo generator is =conduit also beingarranged to discharge circulation of the warmer fluid tangentially to the pump 27, insuring a lubricant around the outer region of the reservoir 11'. In order to further aid in insuring the direction of flow, I may provide a baffle 64 attached to the wall of the reservoir 11 so that the fluid discharge from the conduit 63 is given the desired direction of flow. The direction taken by the circulating fluid around the reservoir is indicated by the arrows. Surrounding the casing of the pump 27 is a-perforated screen which further aids in maintaining a circulation of the oil. Water for cooling the oil is introduced through a conduit 66 into a coil 67 and is discharged after. cooling the oil, through a conduit 68. The coil 67 is so arranged that the water first introduced is present in the inner turnsof the coil and is discharged from the outer turns of the coil. In this manner the warmer circulating oil comes in contact with the coil which has been raised in temperature by the lubricant in the inner region of the reservoir, giving a part of its heat thereto, and later coming into contact with the cooler part of the coil.

The operation of apparatus made in accordance with my. invention will be apparent. The fluid reservoir 11 is filled with some form of lubricating fluid, is closed and the turbine is started. The pump 27 develops fluid under pressure varying with the speed of the turbine and the fluid under a relatively high pressure is delivered through the conduit 39 to the under side of the piston 38, through the branch conduit 48 to the lower sleeve bearing 26 and through the port 58 to the tachometer 19. The fluid pressure acting against the under side of the piston 38 acts in opposition to the force exerted by the spring 43. Increases in speed of the turbine cause an increase in pressure of the fluid acting against the lower side of the piston 38, forcing it upwardly and moving the admission valve 32 in a closing direction. Decreases in speed of the turbine cause a decrease in fluid pressure delivered to the governor and the spring 43' forces the piston 38 downwardly, permitting the incoming motive fluid to open the admission valve 32 wider.

Fluid passing between the restricted portion 51 of the piston 38 and the wall of the spirit thereof, and I desire,

cylinder 37 has its pressure reduced and passes through the port 53. conduit 18' and passage 54 to the upper bearing 24 from whence itdrains back to the reservoir 11 through the passage 56.

To adjust the speed of the turbo-generator to that for which it is designed, the cover 47 is removed and the load on the spring 43 7 is increased or decreased by means of the ad- .Justing nut 44. Increasing the load on the spring 44 increases the operating speed of the turbo-generator, While decreasing the load a decreases the speed. By observing the tachometer 19 the apparatus may be adjusted to the correct operating speed, after which the cover 47 is again replaced. The apparatus will then run for a long period of time without further attention. The nozzle 57 in the volute of the pump 27 insures a continuous circulation of fluid in the reservoir 11 around the cooling coil 67 preventing its overheatirom the foregoing it will be apparent that I have invented an improved turbine having a fluid-pressure operated governor and a forced feed lubricating system associated therewith, capable of close regulation and of running for long periods of time with comparatively little attention.

While I have shown my invention in but two forms, it will beobvious to those skilled in the art that it is not so limited, but is vsusceptible of various other changes and modifications, without departing from the therefore, that only such limitations shall be placed thereupon as are imposed by the prior art or as are specifically set forth in the appended claims.

What I claim is:

1. In a turbine, the combination of a fluidpressure operated governor, means for developing a fluid pressure varying with the speed of the turbine, a bearing lubricated by the fluid employed in the governor, and-means included in the governor for reducing the pressure of the fluid supplied to the bearing.

2. In a turbine, the combination of a rotor, a shaft for the rotor with bearings for the same, a fluid reservoir, a fluid-pressure operated governor, a centrifugal pump submerged Within the fluid reservoir for developing a relatively high fluid pressure varying with the speed of the turbine for the governor, means employing a portion of the fluid under a relatively high pressure for lubricating a part of the bearings, and means included in the governor for reducing the pressure of a part of the fluid employed therein for lubricating another part of the bearings.

3. In a fluid-pressure operated governor for an elastic fluid motor having a pressure operated lubricating system associated therewith, a cylinder providedwith a port leading to a bearing requiring a lubricant at a comparatively low pressure, and an operating piston within the cylinder actuated by the fluid pressure and rovided with a restricted bod portion in registr with the port lead ng to t e bearing for re ucing, in cooperation operating cylinder for the with the walls of the cylinder, the fluid pressure for the bearing.

4. In a turbo-generator system having a shaft, a fluidressure operated governor and a forced fee lubricating system associated therewith, the combination of a fluid reservoir, a centrifugal pump driven by the shaft and immersed within the fluid reservoir, an

overnor communicating with the pump discharge and having a port communicating with the lubricating system, a biased governor piston within the cylinder having a restricted body portion in registry with the port, whereby fluid under a relatively high pressure delivered to the cylinder passes between the restricted body portion of the piston and the cylinder, is reduced in pressure and passes to the lubricatin system.

voir located at the lower end of the shaft, a fluid-pressure operated governor, a centrifugal pump located in the fluid reservoir and having its impeller slidingly connected to the shaft for developing fluid pressure for the governor, and means included in the governor for reducing the fluid pressure developed by ,the pump before its passage to the upper bearing.

8. The combination of a base constituting a fluid reservoir, a separate turbine housing mounted on said base, a shaft in said housing and a turbine rotor on the shaft, bearings for the shaft all carried by the removable turbine housing, said housing including a pump housing projecting downwardly therefrom and having its inlet submerged in the reservoir, and an impeller disposed in said pump housing and driven by said shaft.

In testimony whereof, I have hereunto subscribed my name this twenty-eighth day of November 19%.

I HENRY F. SCHMIDT.

5. he combination with a turbo-generator system having an axis of rotation more vertical than horizontal, of a common shaft, a ball bearing disposed near one end of the shaft and supporting the shaft, a bearing for the opposite end of the shaft, a fluid-pressure operated governor, and a forced feed lubricating system, a fluid reservoir located at the lower end of the turbo-generator, a centrifugal pump having its impeller slidingly connected to the lower end of the shaft and immersed within the fluid reservoir for supplying fluid under a relatively high pressure to l the governor, a iston for the governor subjected on one si e to the relatively high fluid pressure and on the other side to the force exerted by a spring, said piston having a restricted portion extending from the pressure side thereof for a part of its length, and means communicating with the restricted portion of the piston and the bearings, whereby fluid at a reduced pressure is conveyed to the bearings.

6. The combination of a turbine and generator having a common shaft, said shaft being substantially vertical with upper and lower bearings and being so disposed that it rests against one side of the bearings, a fluid reservoir located at the lower end of the shaft a fluid-pressure operated governor, a centri ufial pump located in the fluid reservoir and aving its'impeller slidingly connected to the v shaft for developingfluid pressure for the governor and for lubricating the bearings, and means included in the governor for reducin the fluid pressure developed by the pump e'fore its passage to the bearings.

7. The combination of a turbine and gen= erator having a common shaft, said shaft being substantially vertical with upper and lower bearings and bein so disposed that it rests against one side of t e bearings, a fluid reser 

